It is a kneading eraser for colored pencils suitable for applying delicate colors! Ideally when you want to add shades of color. To improve the quality of creating beautiful works. Tear off as much as you need and knead well until it becomes soft before using.
Kneadable Colored Pencil Eraser
Seed Kneaded Eraser for color pencils is slightly harder than regular kneaded eraser. Great for creating gradient and highlight in your color pencil works.
See here for a solid version of this eraser.